On-site linear polarization resistance mapping of reinforced concrete structures

Corrosion of steel reinforcement embedded in concrete is one of the main causes of degradation of reinforced concrete structures. Degradation occurs in reinforced concrete structures from corrosion caused by the Chloride ingress into concrete. That degradation has a severe impact on the structure in terms of maintenance and rehabilitation costs. Therefore, early detection of reinforcement corrosion is important for efficient maintenance, repair and planning. Meanwhile, the evaluation of the corrosion of reinforcement by non-destructive measurements have been used a lot. In particular CM-II (corrosion meter) is used to measure the polarization resistance, but has some disadvantages. Embedded mini-sensor has been developed in order to overcome these disadvantages. In this study, measurement of corrosion by using the mini-sensor is compared with the measured results by CM-II to verify the validity of the newly developed mini senor. Results show that there are agreement in trends of the parameters measured and as such the developed mini sensor has a promising start to be used.

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Monitoring DIAMOND device for corrosion state evaluation of reinforced concrete structures

MATEC Web of Conferences ◽

10.1051/matecconf/201819904007 ◽

2018 ◽

Vol 199 ◽

pp. 04007 ◽

Cited By ~ 1

Author(s):

Gabriel Samson ◽

Fabrice Deby ◽

Jean-Luc Garciaz ◽

Jean-Louis Perrin

Keyword(s):

Reinforced Concrete ◽

Linear Polarization ◽

Concrete Structure ◽

Polarization Resistance ◽

Reinforced Concrete Structure ◽

Linear Polarization Resistance ◽

Corrosion Evaluation ◽

Ohmic Drop ◽

Concrete Resistivity ◽

Corrosion State

The corrosion of steel rebars is a major issue with respect to the durability of reinforced concrete structure. Several corrosion evaluation methods exist: half-cell potential, concrete resistivity or linear polarization resistance (LPR) measurement. However, these techniques are employed at a given moment and are not suitable for continuous corrosion evaluation. This works belongs to the DIAMOND project which aims to produce a new corrosion state measurement monitoring device. The monitoring probe consists on a cylindrical probe. A ring shape counter-electrode CE is plated on the probe side. At the centre of the CE, a reference electrode (RE) is placed for potential measurement. The device is embedded in concrete at 25 mm of the inspected rebar. The instantaneous ohmic drop observed at the beginning of the polarization measurement is only linked with the concrete resistance which depends on concrete cover and resistivity. A numerical model was developed on Comsol® to create abacuses graph that link concrete resistivity and concrete resistance. Thus, the ohmic drop measure at the beginning of the polarization can now be used to determine regularly concrete average resistivity between the monitoring probe and steel rebar. Two other series of abacus graphs are then introduced in order to determine the polarization resistance of the rebar in front of the monitoring probe (the point of interest (PI)). Two monitoring probes were placed in two types of concrete (one sound concrete and one concrete with chloride). Corrosion potential, concrete resistivity and rebar corrosion rate were monitored over around 200 days. The experimental results obtained with the monitoring probe are finally compared to the results obtained with the surface DIAMOND probe (introduced in the ICCRRR 2018 paper “Alternative methodology for linear polarization resistance assessment of reinforced concrete structure [1]”).

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Remote Measurement of Linear Polarization Resistance In Concrete Structures

MRS Proceedings ◽

10.1557/opl.2016.95 ◽

2016 ◽

Vol 1815 ◽

Author(s):

F. Bernal Castillo ◽

W. Aperador ◽

G. Roa-Rodríguez

Keyword(s):

Linear Polarization ◽

Polarization Resistance ◽

Concrete Structures ◽

Mobile Network ◽

Electrochemical Technique ◽

Remote Measurement ◽

Linear Polarization Resistance ◽

Development Platform ◽

Remote Measurements ◽

Free Development

ABSTRACTThe monitoring of corrosion in reinforced concrete structures is considered an important preventive factor against the corrosive damage. The present paper shows the design and construction of a device which performs remote measurements of the polarization resistance of reinforcing steel, this was made using the electrochemical technique of linear polarization resistance as a method to obtain the information of the corrosive process. The development was carried out by implementing a potentiostat based on a free development platform. The design allows to store all the data on a physical memory and to send the results through the mobile network to a web server, where the measured values can be analyzed using an internet connection.The linear polarization resistance measurements were made in cylindrical concrete specimens with rebars of ½ ”, each one instrumented with embedded electrodes of Copper/Copper sulfate and graphite. The specimens were subjected to a saturated environment of chlorides (3.5%) where the corrosive process was monitored with the developed system. The results were compared with tests performed on a commercial potentiostat / galvanostat, where the values obtained have an mean of 4.83%.

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Alternative methodology for linear polarization resistance assessment of reinforced concrete structure

MATEC Web of Conferences ◽

10.1051/matecconf/201819906009 ◽

2018 ◽

Vol 199 ◽

pp. 06009 ◽

Cited By ~ 1

Author(s):

Gabriel Samson ◽

Fabrice Deby ◽

Jean-Luc Garciaz ◽

Jean-Louis Perrin

Keyword(s):

Reinforced Concrete ◽

Corrosion Rate ◽

Current Density ◽

Linear Polarization ◽

Concrete Structure ◽

Polarization Resistance ◽

Concrete Cover ◽

Reinforced Concrete Structure ◽

Linear Polarization Resistance ◽

Steel Rebar

For reinforced concrete structures, several corrosion detection methods exist: concrete resistivity, half-cell potential or linear polarization resistance (LPR) measurement. The LPR value can be linked to the corrosion rate thanks the Stern-Geary equation if strong hypotheses are made. Existing commercial devices use a guard ring to canalize the current on specific steel rebar area and assume that the steel rebar is uniformly polarized. However, recent works reveal that the top part of the steel rebar, right under the counter electrode, is the most polarized point. The particular point is referred as the point of interest (PI). This works belongs to the DIAMOND project which aims to produce a new corrosion rate measurement device. Comsol® software was used to model the influence of concrete cover, resistivity and injected current on the current density at the PI. Moreover, a significant influence of the steel rebars diameter was also demonstrated. Two types of abacus are built. The first one links to polarization measured on the surface to the polarization on the rebar at the PI. The second links the ratio between the current density at the PI and the density of injected current to concrete cover and steel rebar diameter. The Stern-Geary equation can now be used at the PI without using the approximation of a uniformly polarized rebar. The corrosion state of reinforced concrete structure can be controlled more precisely. The methodology is then applied on two concrete slabs in which three metal bars are embedded at different concrete covers. The first slab is prepared with ordinary concrete while the second contain chloride to artificially activate the corrosion process. The results reveal that the rebars embedded on the first slab are not corroding (icorr ≤0.2 μΑ/cm2) while the second rebar are corroding (icorr>0.2 μΑ/cm2).

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PERBANDINGAN LAJU KOROSI PADA TULANGAN BETON BUSA NORMAL DAN BETON BUSA POZZOLAN

Jurnal Teknik Sipil ◽

10.24815/jts.v1i4.10049 ◽

2018 ◽

Vol 1 (4) ◽

pp. 885-894

Author(s):

Zubaidi Amri ◽

Abdullah Abdullah ◽

Syarizal Fonna

Keyword(s):

Reinforced Concrete ◽

Corrosion Rate ◽

Linear Polarization ◽

Polarization Resistance ◽

Water Immersion ◽

Half Cell ◽

Cell Potential ◽

Linear Polarization Resistance ◽

Foamed Concrete ◽

Potential Mapping

Abstract: Reinforced concrete foam is one alternative to replace conventional reinforced concrete on structural elements. This study aims to measure the The media immersion and variation of specific gravity (SG) is a variable of interest in this study. The specimen type used is Normal foamed concrete (BB) and pozzolan foamed concrete (BBP). The test specimens used were 8 x 8 x 50 cm, with single reinforcement Ø10 mm in it. Reinforced placement of the reinforcement so that the test specimen has a thickness of 4 cm concrete cover. The specimen was immersed in freshwater and artificial seawater in the form of a 3.5% sodium chloride solution. The measurements results using half-cell potential mapping (HCPM) technique described the highest corrosion risk location. At this location corrosion rate measurement performed using linear polarization resistance (LPR) method. The corrosion rate calculation result of normal foamed concrete SG 1,2, 1,4, 1,6 with NaCl 3.5% and fresh water immersion medium ranged from 0,621 mpy up to 0,854 mpy and 0,194 mpy up to 0,304 mpy. The corrosion rate value of pozzolan foamed concrete SG 1,2, 1,4,1,6 with 3.5% NaCl and fresh water immersion media ranges from 0,429 mpy up to 0,545 mpy and 0,072 mpy up to 0,120 mpy. The larger SG value of the foamed concrete specimen used, the less corrosion rate occurs. Corrosion behavior of pozzolan foamed concrete is better than normal foam concrete, this phenomenon occurs due to the effect of adding 10% pozzolan which causes better foamed concrete permeability, so that the resistance of concrete against corrosion increased. In general the corrosion rate of pozzolan foamed concrete in the freshwater environment and corrosive environment (artificial seawaters of NaCl 3.5%) is smaller than the corrosion rate of normal foamed concrete. Abstrak: Beton busa bertulang merupakan salah satu alternatif untuk menggantikan beton bertulang konvensional pada elemen struktural. Penelitian ini bertujuan untuk mengukur laju korosi pada beton busa bertulang. Media rendaman dan variasi berat jenis (SG) merupakan variabel yang ditinjau dalam penelitian ini. Jenis benda uji yang digunakan berupa beton busa normal (BB) dan beton busa pozzolan (BBP). Benda uji yang digunakan berbentuk balok 8 x 8 x 50 cm, dengan tulangan tunggal Ø10 mm didalamnya. Dilakukan penempatan tulangan sehingga benda uji memiliki ketebalan selimut 4 cm. Benda uji direndam menggunakan air tawar dan air laut buatan berupa larutan Natrium Clorida 3,5%. Hasil pengukuran menggunakan teknik half-cell potential mapping (HCPM) menggambarkan lokasi yang memiliki resiko tertinggi terkorosi. Pada lokasi ini dilakukan pengukuran laju korosi dengan menggunakan metode linear polarization resistance (LPR). Hasil perhitungan laju korosi pada beton busa normal SG 1,2 sampai 1,6 dengan media rendaman larutan NaCl 3,5% dan air tawar berkisar antara 0,621 mpy sampai dengan 0,854 mpy dan 0,194 mpy sampai dengan 0,304 mpy. Nilai laju korosi pada beton busa pozzolan SG 1,2, 1,4, 1,6 dengan media rendaman NaCl 3,5% dan air tawar berkisar antara 0,429 mpy sampai dengan 0,545 mpy dan 0,072 mpy sampai dengan 0,120 mpy. Semakin besar nilai SG benda uji beton busa yang digunakan, maka laju korosi yang terjadi semakin kecil. Perilaku korosi beton busa pozzolan lebih baik dari pada beton busa normal, fenomena ini terjadi akibat pengaruh penambahan 10% pozzolan yang menyebabkan permeabilitas beton busa semakin baik sehingga ketahan beton terhadap korosipun semakin meningkat. Secara umum laju korosi pada beton busa pozzolan dilingkungan air tawar dan lingkungan korosif (air laut buatan NaCl 3,5%) lebih kecil dibandingkan laju korosi beton busa normal.

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Techniques for measuring the corrosion rate (polarization resistance) and the corrosion potential of reinforced concrete structures

Non-Destructive Evaluation of Reinforced Concrete Structures ◽

10.1533/9781845699604.2.284 ◽

2010 ◽

pp. 284-316 ◽

Cited By ~ 3

Author(s):

C. Andrade ◽

I. Martínez

Keyword(s):

Reinforced Concrete ◽

Corrosion Rate ◽

Polarization Resistance ◽

Corrosion Potential ◽

Concrete Structures ◽

Reinforced Concrete Structures

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Embedded Sensors for Corrosion Monitoring of Existing Reinforced Concrete Structures

Materials Science Forum ◽

10.4028/www.scientific.net/msf.587-588.677 ◽

2008 ◽

Vol 587-588 ◽

pp. 677-681 ◽

Cited By ~ 5

Author(s):

E.V. Pereira ◽

R.B. Figueira ◽

Manuela M. Salta ◽

I.T.E. Fonseca

Keyword(s):

Reinforced Concrete ◽

Corrosion Rate ◽

Polarization Resistance ◽

Concrete Structures ◽

Steel Corrosion ◽

Embedded Sensors ◽

Corrosion Monitoring ◽

Reinforced Concrete Structures ◽

Reinforcement Corrosion ◽

Galvanic Current

In this work the performance of two surface treatments and the efficiency of a corrosion inhibitor were evaluated, in the control of steel corrosion in concrete induced by chlorides, through measurements of galvanic current and polarization resistance applied to embedded sensors fixed in existing concrete using different methodologies. From the results obtained the use of the different embedded sensors in the measurement of corrosion rate is discussed aiming the development of new systems for permanent evaluation of the on site performance of products for repairing reinforced concrete structures affected by reinforcement corrosion.

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Design of precast reinforced concrete structures of frame buildings: a new set of rules

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.04.04-09 ◽

2019 ◽

pp. 4-9 ◽

Cited By ~ 1

Keyword(s):

Reinforced Concrete ◽

Concrete Structures ◽

Reinforced Concrete Structures ◽

Building Frames ◽

Fine Grained ◽

Rigid Frame ◽

Floor Slabs ◽

Frame Buildings ◽

Spatial System ◽

Precast Elements

Currently, prefabricated reinforced concrete structures are widely used for the construction of buildings of various functional purposes. In this regard, has been developed SP 356.1325800.2017 "Frame Reinforced Concrete Prefabricated Structures of Multi-Storey Buildings. Design Rules", which establishes requirements for the calculation and design of precast reinforced concrete structures of frame buildings of heavy, fine-grained and lightweight structural concrete for buildings with a height of not more than 75 m. The structure of the set of rules consists of eight sections and one annex. The document reviewed covers the design of multi-story framed beam structural systems, the elements of which are connected in a spatial system with rigid (partially compliant) or hinged joints and concreting of the joints between the surfaces of the abutting precast elements. The classification of structural schemes of building frames, which according to the method of accommodation of horizontal loads are divided into bracing, rigid frame bracing and framework, is presented. The list of structural elements, such as foundations, columns, crossbars, ribbed and hollow floor slabs and coatings, stiffness elements and external enclosing structures is given; detailed instructions for their design are provided. The scope of the developed set of rules includes all natural and climatic zones of the Russian Federation, except seismic areas with 7 or more points, as well as permafrost zones.

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Improvement Of Curvilinear Diagrams Of Concrete Deformation

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.08.99-104 ◽

2019 ◽

pp. 99-104

Keyword(s):

Reinforced Concrete ◽

Peak Load ◽

Experimental Studies ◽

Concrete Structures ◽

Deformation Model ◽

Reinforced Concrete Structures ◽

Significant Difference ◽

Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

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